Plugin Overview

MariaDB supports the use of plugins, software components that may be added to the core software without having to rebuild the MariaDB server from source code. Plugins can be loaded at startup, or loaded and unloaded while the server is running, without interruption. Plugins are commonly used for adding desired storage engines, additional security requirements, logging special information about the server, or even small enhancements, such as a plugin to get a timestamp as an integer.

Querying Plugin Information

There are a number of ways to see which plugins are currently active.

A server almost always has a large number of active plugins, because the server contains a large number of built-in plugins, which are active by default and cannot be uninstalled.

Querying Plugin Information with SHOW PLUGINS

The statement can be used to query information about all active plugins.

For example:

If a plugin's Library column has a NULL value, then the plugin is built-in, and it cannot be uninstalled.

Querying Plugin Information with information_schema.PLUGINS

The table can be queried to get more detailed information about plugins.

For example:

If a plugin's PLUGIN_LIBRARY column has the NULL value, the plugin is built-in and cannot be uninstalled.

Querying Plugin Information with mysql.plugin

The table can be queried to get information about installed plugins.

This table only contains information about plugins that have been installed via the following methods:

• The statement.

• The statement.

• The utility.

This table does not contain information about:

• Built-in plugins.

• Plugins loaded with the option.

• Plugins loaded with the option.

This table only contains enough information to reload the plugin when the server is restarted, which means it only contains the plugin name and the plugin library.

For example:

Installing a Plugin

There are three primary ways to install a plugin:

• A plugin can be installed dynamically with an SQL statement.

• A plugin can be installed with a option, but it requires a server restart.

• A plugin can be installed with the utility, while the server is completely offline.

When you are installing a plugin, you also have to ensure that:

• The server's plugin directory is properly configured, and the plugin's library is in the plugin directory.

• The server's minimum plugin maturity is properly configured, and the plugin is mature enough to be installed.

Installing a Plugin Dynamically

A plugin can be installed dynamically by executing either the or the statement.

If a plugin is installed with one of these statements, a record will be added to the table for the plugin. This means that the plugin will automatically be loaded every time the server restarts, unless specifically uninstalled or deactivated.

Installing a Plugin with INSTALL SONAME

You can install a plugin dynamically by executing the statement. installs all plugins from the given plugin library. This could be required for some plugin libraries.

For example, to install all plugins in the server_audit plugin library (which is currently only the audit plugin), you could execute the following:

Installing a Plugin with INSTALL PLUGIN

You can install a plugin dynamically by executing the statement. installs a single plugin from the given plugin library.

For example, to install the audit plugin from the server_audit plugin library, you could execute the following:

Installing a Plugin with Plugin Load Options

A plugin can be installed with a option by providing either the or the option.

If a plugin is installed with one of these options, then a record will not be added to the table for the plugin. This means that if the server is restarted without the same option set, then the plugin will not automatically be loaded.

Installing a Plugin with --plugin-load-add

You can install a plugin with the option by specifying the option as a command-line argument to or by specifying the option in a relevant server in an .

The --plugin-load-add option uses the following format:

• Plugins can be specified in the format name=library, where name is the plugin name and library is the plugin library. This format installs a single plugin from the given plugin library.

• Plugins can also be specified in the format library, where library is the plugin library. This format installs all plugins from the given plugin library.

For example, to install all plugins in the server_audit plugin library (which is currently only the audit plugin) and also the authentication plugin from the auth_ed25519 plugin library, you could set the option to the following values on the command-line:

You could also set the option to the same values in an :

Special care must be taken when specifying both the option and the option together. The --plugin-load option resets the plugin load list, and this can cause unexpected problems if you are not aware. The --plugin-load-add option does not reset the plugin load list, so it is much safer to use. See for more information.

Installing a Plugin with --plugin-load

You can install a plugin with the option by specifying the option as a command-line argument to or by specifying the option in a relevant server in an .

The --plugin-load option uses the following format:

• Plugins can be specified in the format name=library, where name is the plugin name and library is the plugin library. This format installs a single plugin from the given plugin library.

• Plugins can also be specified in the format library, where library is the plugin library. This format installs all plugins from the given plugin library.

For example, to install all plugins in the server_audit plugin library (which is currently only the audit plugin) and also the authentication plugin from the auth_ed25519 plugin library, you could set the option to the following values on the command-line:

You could also set the option to the same values in an :

Special care must be taken when specifying the --plugin-load option multiple times, or when specifying both the --plugin-load option and the --plugin-load-add option together. The --plugin-load option resets the plugin load list, and this can cause unexpected problems if you are not aware. The --plugin-load-add option does not reset the plugin load list, so it is much safer to use. See for more information.

Specifying Multiple Plugin Load Options

Special care must be taken when specifying the --plugin-load option multiple times, or when specifying both the --plugin-load option and the --plugin-load-add option. The --plugin-load option resets the plugin load list, and this can cause unexpected problems if you are not aware. The --plugin-load-add option does not reset the plugin load list, so it is much safer to use.

This can have the following consequences:

• If the --plugin-load option is specified multiple times, then only the last instance will have any effect. For example, in the following case, the first instance of the option is reset:

• If the --plugin-load option is specified after the --plugin-load-add option, then it will also reset the changes made by that option. For example, in the following case, the --plugin-load-add option does not do anything, because the subsequent --plugin-load option resets the plugin load list:

• In contrast, if the --plugin-load option is specified before the --plugin-load-add option, then it will work fine, because the --plugin-load-add option does not reset the plugin load list. For example, in the following case, both plugins are properly loaded:

Installing a Plugin with mariadb-plugin

A plugin can be installed with the utility if the server is completely offline.

The syntax is:

For example, to install the audit plugin, you could execute the following:

If a plugin is installed with this utility, a record will be added to the table for the plugin. This means that the plugin will automatically be loaded every time the server restarts, unless specifically uninstalled or deactivated.

Configuring the Plugin Directory

When a plugin is being installed, the server looks for the plugin's library in the server's plugin directory. This directory is configured by the plugin_dir system variable. This can be specified as a command-line argument to or it can be specified in a relevant server in an :

Configuring the Minimum Plugin Maturity

When a plugin is being installed, the server compares the plugin's maturity level against the server's minimum allowed plugin maturity. This can help prevent users from using unstable plugins on production servers. This minimum plugin maturity is configured by the system variable. This can be specified as a command-line argument to or it can be specified in a relevant server in an :

Configuring Plugin Activation at Server Startup

A plugin will be loaded by default when the server starts if:

• The plugin was installed with the statement.

• The plugin was installed with the statement.

• The plugin was installed with the utility.

• The server is configured to load the plugin with the option.

This behavior can be changed with special options that take the form --plugin-name. For example, for the audit plugin, the special option is called .

The possible values for these special options are:

A plugin's status can be found by looking at the PLUGIN_STATUS column of the table.

Uninstalling Plugins

Plugins that are found in the mysql.plugin table, that is those that were installed with , or can be uninstalled in one of two ways:

• The or the statement while the server is running

• With while the server is offline.

Plugins that were enabled as a --plugin-load option do not need to be uninstalled. If --plugin-load is omitted the next time the server starts, or the plugin is not listed as one of the --plugin-load entries, the plugin will not be loaded.

uninstalls a single installed plugin, while uninstalls all plugins belonging to a given library.

See Also

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